You have come to the right place for advice, our hobby's luminaries are all on board here. You might try asking "gunrunnerjohn"* about your LED issues, he's an electronics genius and is always very helpful.
Its good that you used expandable benchwork. You'll find that these things tend to grow. Though O Gauge takes up twice the space of HO, you have the satisfaction of having the floor shake when a train goes by. Gauging from your "profile" photo, you're a 1:1 railroader and you'll find a lot of us here, too. I just wish you'd chosen "The First and Finest" for your road...
As a CNW Engineer used to broadcast across the entire Galena Division, every day, regardless of hour or assignment,
"Its a beautiful day to be railroading!"
Enjoy!